超密集网络是第五代移动通信系统提升容量的关键技术之一。针对基站密集部署场景，考虑用户基于多连接用户归属方式接入多个基站，以充分利用基站资源。为进一步提高用户吞吐量，研究多连接场景下的用户归属与功率控制策略。从兼顾系统吞吐量与用户公平性角度出发，将问题建模成对数速率最大化问题。通过将优化问题分解为用户归属和功率控制两个子问题，得出一种高效的次优解法。仿真结果表明所提算法在系统吞吐量上较已有算法具有明显的增益。
Ultra-dense network is one of the key technologies to improve the capacity of the fifth generation mobile communication system. In this work, we assume that one user can connect to multiple base stations to make full use of the stations. In order to further improve the throughput of the system using more base stations, we study user-association and power-control in the multiple association condition. To consider the network throughput and the equality of users, we model this problem as a problem of maximizing the logarithm of user rate. Since this problem is difficult to solve, we divide this problem into two subproblems, which can be solved efficiently. Simulation results reveal that the proposed algorithm is better than the existing algorithms in system performance.
[1] Shi Y, Zhang J, Letaief K B, et al. Large-scale convex optimization for ultra-dense Cloud-RAN[J]. IEEE Wireless[KG3*4] Communications, 2015, 22(3):84-91.
[2] Hwang I, Song B, Soliman S S. A holistic view on hyper-dense heterogeneous and small cell networks[J]. IEEE Communications Magazine, 2013,51(6):20-27.
[3] Kamel M I, Hamouda W, Youssef A M. Multiple association in ultra-dense networks[C]//Communications (ICC), 2016 IEEE International Conference on. IEEE, 2016:1-6.
[4] Jin Y, Qiu L. Joint user association and interference coordination in heterogeneous cellular networks[J]. IEEE Communications Letters, 2013, 17(12):2296-2299.
[5] Jia Y, Zhao M, Zhou W. Joint User Association and eICIC for Max-Min Fairness in HetNets[J]. IEEE Communications Letters, 2016, 20(3):546-549.
[6] Ikeda Y, Okasaka S, Hoshino M, et al. Proportional fair-based joint optimization of cell association and inter-cell interference coordination for heterogeneous networks[C]//2014 IEEE 80th Vehicular Technology Conference (VTC2014-Fall). IEEE, 2014:1-5.
[7] Lin Y, Yu W. Optimizing user association and frequency reuse for heterogeneous network under stochastic model[C]//2013 IEEE Global Communications Conference (GLOBECOM). IEEE, 2013:2045-2050.
[8] Chiang P H, Huang P H, Sun S S, et al. Joint power control and user association for traffic offloading in heterogeneous networks[C]//2014 IEEE Global Communications Conference. IEEE, 2014:4424-4429.
[9] Sun R, Hong M, Luo Z Q. Joint downlink base station association and power control for max-min fairness:Computation and complexity[J]. IEEE Journal on Selected Areas in Communications, 2015, 33(6):1040-1054.
[10] 徐茂, 张光荣, 陈晓辉, 等. 基于调和均值公平的多小区干扰协调功率分配算法[J]. 中国科学院大学学报, 2012, 29(5):659-666.
[11] 余林浩, 卢汉成, 洪佩琳. 一种带QoS约束的资源分配和ABS功率控制算法[J]. 中国科学院大学学报, 2015, 32(5):661-666.
[12] Park J, Kim S L, Zander J. Asymptotic behavior of ultra-dense cellular networks and its economic impact[C]//2014 IEEE Global Communications Conference. IEEE, 2014:4941-4946.
[13] Stefanatos S, Alexiou A. Access point density and bandwidth partitioning in ultra dense wireless networks[J]. IEEE transactions on communications, 2014, 62(9):3376-3384.
[14] Ding M, López-Pérez D, Mao G, et al. Will the area spectral efficiency monotonically grow as small cells go dense?[C]//2015 IEEE Global Communications Conference (GLOBECOM). IEEE, 2015:1-7.
[15] Hovgaard T G, Boyd S, Larsen L F S, et al. Nonconvex model predictive control for commercial refrigeration[J]. International Journal of Control, 2013, 86(8):1349-1366.
